So are both your internet connections ADSL lines? I had assumed that only one of them is. If they are both ADSL lines then you would connect one of them to the ADSL port of your Draytek. The other one needs to be changed into an ethernet type connection and connected to the WAN2 port of your Draytek. The way this is normally done is that you order the ADSL connection in a non-NAT configuration and the ISP supplies you with a router that provides public IP addresses on it's ethernet output.

Have a look at this Demon product where you will see that there is a non-NAT option.

The way you get it is to talk to your ISP. If you are using a business grade product then the cost for NAT and non-NAT is usually the same. If you are using consumer grade ADSL and only have the option of one IP address then you need to find an ADSL modem which supports 'half bridging' or 'DHCP spoofing' so that it can pass the single public IP address through to the WAN2 port of your Draytek. Failing that you will have to put up with double NATing, which is not very efficient.

Kevin

KevinGB wrote: So are both your internet connections ADSL lines? I had assumed that only one of them is. If they are both ADSL lines then you would connect one of them to the ADSL port of your Draytek. The other one needs to be changed into an ethernet type connection and connected to the WAN2 port of your Draytek. The way this is normally done is that you order the ADSL connection in a non-NAT configuration and the ISP supplies you with a router that provides public IP addresses on it's ethernet output.

Have a look at this Demon product where you will see that there is a non-NAT option.

The way you get it is to talk to your ISP. If you are using a business grade product then the cost for NAT and non-NAT is usually the same. If you are using consumer grade ADSL and only have the option of one IP address then you need to find an ADSL modem which supports 'half bridging' or 'DHCP spoofing' so that it can pass the single public IP address through to the WAN2 port of your Draytek. Failing that you will have to put up with double NATing, which is not very efficient.

Kevin

Kevin, Great information and many thanks. Both DSL lines are connected to user grade broadband services. I can turn off NAT on one router, would that help?

Also would i be able to use DHCP Spoofing or half briding using another draytek? I have a spare 2600 Draytek which I could easily use for delivering the service across O2 broadband.

Just a question on the WAN2 port. I am guessing all the port needs or requires is an associated IP address and a default gateway which is associated with the secondary router? I have tried this before and could not route between the two subnets? Even though RIP was enabled.

Thanks for your patience. I am trying to work this out in my head so I can understand how the two internal IP subnets will talk and how any subnet (private IP) will be able to route to either Internet gateway.

Thanks again
G

The WAN2 port of your Draytek and the LAN side port of your secondary connection need to be able to talk to each other. This could be by using 2 public IP addresses in the same subnet, 2 private IP addresses in the same subnet, or a box which allows a single public IP address to be allocated to the WAN2 port.

The way things would work is this:

Somebody on your LAN makes an internet connection, say to a web site. The Draytek decides which internet connection to use based on load and any quality of service rules that have been setup. It translates the IP address in the headers of the outgoing packets using NAT, so that they only contain the IP address of the WAN port that they are being transmitted through. That would normally be a public IP address, but it could also be a private IP address corresponding to another router which will do NAT again.

Note that this is a one way process. The Draytek is acting as a firewall. You can't connect something to WAN ports of the Draytek and then start pinging PCs on your LAN unless you set up some means of passing through the connection, such as port mapping.

Consider this image:

The PC on the LAN would get a private IP address from the Draytek using DHCP, something like 192.168.1.100 and it would use the Draytek as its default gateway at say 192.168.1.1.
The ADSL connection will get a public IP address and default gateway from the Primary ADSL connection.
The ADSL modem will get a public IP address and default gateway from the Secondary ADSL connection.
If the ADSL modem is configured as a half bridge then it will just pass this information to the WAN2 port and that public IP address will be used by the Draytek on WAN2.
If it can't act as a half bridge then it will use a private IP address pool on its internal side. For example it could have the IP address 192.168.2.1 and the WAN2 port of the Draytek could use 192.168.2.100 with 192.168.2.1 as its default gateway. The Draytek would pick up this information from the ADSL modem using DHCP. This is the situation where you would get double NATing.

Kevin thanks so much for the perfect explanation. I will go home tonight and give your solution a try.

Very kind of you to spend the time explaining and providing the appropriate diagram as well. So big thanks.

I will take a look at my Draytek documentation and see if half bridging is supported.

I am guessing the Public allocated IP address is always available anyway? So what if you turned NAT of the secondary DSL Router. Would that simplify the design?

Thanks again.
G

I think you would find that if you just turned NAT off then the router would do true routing and so you would need two public IP addresses in the same subnet - one for use by the router and a second for use by the Draytek. However, it may be that your router will act as a half bridge if you turn NAT off, so it is worth experimenting and RTFM (read the f**g manual). You can also google the model of your router and 'half bridge' because somebody is bound to have tried it. Before you turn a box into a half bridge you would need to check how you go about reconfiguring it - what I mean is if it isn't using an IP address itself then how do you connect to it to reconfigure it. Again RTFM.

Kevin

Status so far.

Ok Kevin after taking your advice the status so far is I am slowly getting there

I now have two Draytek 2820Vn routers.

1 connected to BT Openworld

1 connected to O2

My BT Openworld router is my main router which will basically carry out the load-balancing

WAN2 is connected to an ethernet connection on the 2nd Draytek at 100Mbps.

For simplicity at present and to help with configuration the BT draytek has a 192.168.0.1/24 default gateway.

The O2 router has 192.168.0.254/24. The O2 Router also has PPOE enabled, which after reading draytek forums is required by the slave router?

Once I am happy with connectivity I then switch the ethernet connection on the primary BT draytek to WAN2. I disabled the BT broadband connection and successfully routed traffic across the WAN2 port! Excellent.

However, I have hit another snag I was wondering if someone could help me with? Any computers directly connected to the secondary router can not receive a DHCP address and cannot ping 192.168.0.1 (master Router)?

I have tried setting up RIP on both routers with no success. I can see in the routing table that the default gateway is seen by the remote router, and vice-versa. Can anyone tell me what I am doing wrong please?

Have I missed something?

I also realise that the Draytek connected to the O2 dsl service could be enabled in Bridge Mode, if I had a true ADSL2+ service but I currently do not, and there is nowhere available to add in login credentials when trying to configure in bridge mode.

Any help or advice would be greatly appreciated.

G